I get this a bit about Angus as he has an olive complexion and thick dark brown hair and he looks totally different from his brothers. I have the dark hair but not the skin tone. I have pasty white and freckly Irish skin.
Most ask if he has a different father (no ) and the funny thing is that my DH was the odd looking one from his family being the only fair skinned redhead and his mum used to cop the same questions!

If people really push it I tell them there is Maori and Lebanese going back a few generations (which there is on MIL's side) so he is a genetic throwback Never had anything bad said about it just nodding and wow how interestings!